Air conditioning unit



Feb. 28, 1967 c c, R ET AL 3,306,070

AIR CONDITIONING UNIT Filed Oct. 24, 1965 glam INVENTORS. CARL c. HERB. FIG. 2 DAVID F. BRYANS.

ATTORNEY.

United States Patent 3,306,070 AIR CONDITIONING UNIT Carl C. Herb, Cazenovia, and David F. Bryans, Syracuse, N.Y., assignors to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Oct. 24, 1965, Ser. No. 504,934 7 Claims. (Cl. 62285) This invention relates to an air conditioning unit and, more particularly, to a room terminal base unit for use in an air conditioning system.

Room terminals may be furred into a wall or mounted in a cabinet suspended from a ceiling for the passage of cool air from the terminal into a space having a cooling requirement. Installation and servicing of such a unit generally involves overhead work. For example, servicing is often complicated because of difliculty in removing and replacing various parts and in some instances dismounting of the entire base unit may be required.

It is a primary object of this invention to provide a new and improved air conditioning unit and, more particularly, a room terminal base unit. A related object is provision of such a unit which is lightweight and may be conveniently installed and serviced. Another related object is provision of such a unit in which various components may be installed and removed from below the mounted unit.

These and other objects and advantages of the invention will be apparent from the following description and the accompanying drawing in which:

FIGURE 1 is a perspective view of a room terminal base unit embodying features of the invention;

FIGURE 2 is a sectional view taken generally on the line IIII in FIGURE 1; and

FIGURES 3 and 4 are enlarged, fragmentary sectional views taken generally along the lines III III in FIG- URE 1 and IV1V in FIGURES 1 and 2 respectively.

Referring particularly to FIGURE 1 of the drawing, the illustrated room terminal base unit includes a casing 11 having an air passage 12 formed by a body 13 and a drain pan 14 having a bottom surface 15 declining rearwardly and across the body to a drain fitting 16 mounted in a rear wall 17 of the pan for disposing of moisture from portions of the unit. Sufiicient itch is provided the drain pans bottom surface 15 so that only the corner of the pan at the drain fitting 16 need be water tight, rather than all four corners in most pans. Suitable blower means 18 at a rear end of the casing 11 force air through a cooling coil 19 mounted across the passage 12 with the cooled air leaving the passage through a discharge portion 20 at the front of the casing. A top wall 21 of the casing is formed with outwardly extending flanges 22 having suitable apertures 23 for receiving mounting lugs or hangers suspending the base unit from an overhead support, such as a building ceiling (not shown) or the top of a suitable cabinet (not shown) which may encase the base unit.

In the illustrated embodiment the coil 19 includes opposed tube sheets 24, only one being illustrated. Tubes 25 are mounted in the tube sheets 24 and communicate with headers 26 (FIGURE 1) having nipples 27 for connection with a chilled water line (not shown) to circulate chilled water through the tubes 25. Fins 28 (FIGURES 2 and 3) are preferably mounted on the tubes 25 within the air passage 12 for optimum heat transfer between the air to be cooled and the coil 19.

The casing body 13 includes opposed end walls 29 connected by the top wall 21 and a rear wall 29a with thermal insulation 30 on their inner surfaces, each end wall having a forwardly inclined slot 31 opening through a bottom edge 32 (FIGURE 4) of the wall. Parallel inwardly directed flanges 33 extend from the sides of each slot 31, and parallel flanges 34 (FIGURE 3) extend outwardly from opposite side edges of each tube sheet 24. The coil flanges 34 slide along and embrace the adjacent end wall flanges 33 as the coil is moved upwardly in the casing body 13 and into tight abutting engagement with pliable thermal insulation 35 (FIGURE 2) on the inside of the top wall 21 of the casing and, more particularly, on a forwardly declining portion 36 of the top wall. The nested flanges 33 and 34 form baflle means which substantially prevent the escape of air from the passage through the slots 31 in the walls 29 and restrain the operatively positioned coil 19 against substantial move ment relative to the casing 11. Portions of the coil 19, such as return bends of the tubes 25, the headers 26 and nipples 27 protrude outwardly through the slots 31.

The coil 19 has a coil support 37 which is suitably secured to the lower ends of the tube sheets 24 and is preferably in substantially abutting engagement with the coil fins 28. The support 37 extends between the opposed walls 29 with a generally horizontal portion 38 of the support detachably secured at either end to inwardly extending flanges 40 at bottom edges 32 of either wall 29, as by self-tapping metal screws 39 accessible from below the unit with the drain pan 14 removed. A front edge 41 of the coil support 37 is in abutting relationship with and indents (FIGURE 2) a pliable or crushable thermal insulating plate 42 which forms the inner bottom surface 15 of the drain pan 14 and the bottom surface of the air passage 12 through the casing 11, for substantially preventing passage of air between the bottom of the coil 19 and the casing. The insulating plate 42 rests on a sheet metal bottom wall 43 of the drain pan 14 and caulking is provided extending up the pan walls at the plate end and rear edges for substantially preventing cold moisture on the bottom surface 15 of the pan from reaching and chilling the bottom wall 43 sufficiently for the formation of condensate on the outside surface 44 of the bottom wall.

The drain pan 14 is operatively assembled on the casing body 13 by means of a generally L-shaped rearwardly facing abutment 45 of a structural member 46 connecting the end walls 29 at the bottom of the front or discharge portion 20 of the body 13 and providing an abutment on which rests a depending lower edge portion 47 (FIGURE 2) of a front wall 48 of the drain pan. (Because of sub stantial pitch of the bottom surface 15, the front wall 48 need not retain water.) The rear wall 17 of the drain pan 14 is detachably secured to a depending flange 49 of the coil support 37 by suitable releasable interlocked means such as bolts 50 extending through holes in the rear wall 17 of the drain pan and threadedly engaging nuts 51 fixedly secured on the depending flange 49 of the coil support, thus eliminating need for support members extending through the insulating plate 42, as in many units. The holes in rear wall 17 are arranged with the hole nearest the drain fitting 16 farther above the surface 15 of insulating plate 42 than the hole farthest away from the drain fitting, and the nuts 51 are mounted on the coil support in the same horizontal plane when the unit is installed, to pitch the bottom surface 15 downwardly toward the drain fitting. The end wall edges 32 are preferably horizontally aligned, and the edge 32 farthest from the drain fitting 16 indents farther into the insulating plate 42 than the end wall edge 32 nearest the fitting 16. Similarly, the front edge 41 of the coil support 37 indents the plate 42 increasing amounts farther from the fitting 16. By horizontal mounting of the nuts 51 and by provision of the end wall edges 32 horizontally aligned, a drain pan with its fitting 16 at either end of the body 13 may be mounted on the same body 13 and coil support 37 with the pan bottom surface 15 properly pitched toward the drain fitting.

The bolts 50 are easily accessible from below the suspended unit and upon tightening these bolts the rear flanges 33 of the opposed walls 29 are moved rearwardly toward the rear tube sheet flanges 34 for retaining the coil 19 in place and substantially preventing leakage of air, and the front wall 48 adjacent the edge portion 47 of the drain pan 14 is tightly clamped against the L- shaped abutment 45. A front edge 52 (FIGURE 2) of the bottom plate 42 is exposed through a recess in the drain pan front wall 48 and is urged into tight engagement with a relatively softer insulating strip 53 extending across the member 46. The strip 53 abuts and extends slightly above a generally vertical front lip 54 of the structural member 46, and extends rearwardly of a horizontal offset 55 adjacent the lip 54. As the strip is compressed, it bulges over the top edge of the lip 54 and the front of the plate 42, and substantially prevents the stream of cold air contacting the lip so that heat conduction through the structural member 46 is sufliciently retarded to substan tially prevent formation of condensate on the outside of this member which is kept warm by ambient air. The recess in the pan front wall similarly prevents the stream of chilled air in the passage 12 from contacting and chilling the front wall and the pan bottom wall 43. The bottom edges 32 of the opposed walls 29 forward of the coil 19 indent the insulating plate 42 of the drain pan 14 for substantially preventing air flow from the air passage 12 and securing the forward portion of the walls. The abutment of end wall edges 32 and coil support front edge 41 with the insulating plate 42 holds the insulating plate in place in drain pan 14 without the use of adhesive.

Since the drain pan 14 provides the bottom surface 15 of the casing 11 and the air passage 12, an appreciable savings in weight and material is realized and servicing of the unit is greatly facilitated. For example, in order to remove the drain pan 14, it is merely necessary to release the bolts 50 from below the installed unit, whereupon the pan may be dismounted from the casing body 13. By releasing the screws 39 at either end of the coil support 37, and disconnecting the connections between the chilled water line and the nipples 27, the coil 19 may be slipped downwardly and removed from the casing 11. Upon reassembling the unit, sliding the coil flanges 34 upwardly along the end wall fianges 33 moves the top portion of the coil into sealing engagement with insulation 35 on the inside of the casing body top wall inclined portion 36 and the screws 39 are replaced to secure the coil 19 in place. The front edge portion 47 of the drain pan 14 is rested on the L-shaped abutment 45 and the drain pan securing bolts 50 are tightened in place to move the end wall flanges 33 into proper relationship with the tube sheet flanges 34, and to seat the wall bottom edges 32 and the coil support front edge 41 on the drain pan bottom plate 42, thus operatively positioning the drain pan on the casing body 13.

While a preferred embodiment of the invention has been described and illustrated, it should be understood that the invention is not limited thereto but may be otherwise embodied within the scope of the following claims,

We claim:

1. An air conditioning unit comprising a casing including a body having opposed walls, means including a drain pan for receiving moisture from portions of the unit and cooperating with said Walls to provide a passage adapted to pass air through the casing, said drain pan forming a bottom surface of said passage, assembly means detachably mounting said drain pan on said body, a coil in said passage adapted to cool the air passing through said passage, and mounting means mounting said coil operatively positioned in said passage, said mounting means including a support extending between the opposed walls in substantial abutting engagement with the coil, and first means on said coil adapted to cooperate with means similar to the first means on said opposed walls to prevent substantial escape of air between the coil and the opposed walls.

2. A unit according to claim 1 in which said opposed walls have bottom edges in abutting relationship with said bottom surface to provide a tight joint between said opposed walls and said bottom surface.

3. A unit according to claim 1 in which the support extends between said opposed walls in abutting relationship with said bottom surface of said drain pan to provide a tight joint between the coil and the bottom surface.

4. A unit according to claim 1 in which said drain pan has a pliable thermal insulating bottom plate to retard formation of condensate on the drain pan and said bottom plate provides said bottom surface, said opposed walls have bottom edges, and said bottom edges of said opposed walls and said support indent in said bottom plate to provide tight joints between the opposed walls and coil, and said bottom surface.

5. A unit according to claim 4 in which said assembly means includes cooperating abutment means on said body and said drain pan detachably holding a first portion of said drain pan on said body, and detachably interlocked means releasable from below the unit at a second portion of said drain pan opposite said first portion for releasably securing said pan to said body and retaining said cooperating abutment means in position.

6. A unit according to claim 1 in which said assembly means includes cooperating abutment means on said body and said drain pan holding a first portion of said drain pan on said body, and detachably interlocked means at a second portion of said drain pan releasably securing said pan to said body.

7. A unit according to claim 6 in which said detachably interlocked means comprises means releasable from below the unit.

References Cited by the Examiner UNITED STATES PATENTS 1,917,043 7/1933 Lewis 62426 2,148,238 2/ 1939 Krackowizer 62426 2,266,373 12/1941 Marlo 62--426 2,323,176 6/1943 Ashley 62426 3,112,623 12/1963 Crossman 62426 3,174,301 3/1965 Thornton 62291 I. WYE, Primary Examiner, 

1. AN AIR CONDITIONING UNIT COMPRISING A CASING INCLUDING A BODY HAVING OPPOSED WALLS, MEANS INCLUDING A DRAIN PAN FOR RECEIVING MOISTURE FROM PORTIONS OF THE UNIT AND COOPERATING WITH SAID WALLS TO PROVIDE A PASSAGE ADAPTED TO PASS AIR THROUGH THE CASING, SAID DRAIN PAN FORMING A BOTTOM SURFACE OF SAID PASSAGE, ASSEMBLY MEANS DETACHABLY MOUNTING SAID DRAIN PAN ON SAID BODY, A COIL IN SAID PASSAGE ADAPTED TO COOL THE AIR PASSING THROUGH SAID PASSAGE, AND MOUNTING MEANS MOUNTING SAID COIL OPERATIVELY POSITIONED IN SAID PASSAGE, SAID MOUNTING MEANS INCLUDING A SUPPORT EXTENDING BETWEEN THE OPPOSED WALLS IN SUBSTANTIAL ABUTTING ENGAGEMENT WITH THE COIL, AND FIRST MEANS ON SAID COIL ADAPTED TO COOPERATE WITH MEANS SIMILAR TO THE FIRST MEANS ON SAID OPPOSED WALLS TO PREVENT SUBSTANTIAL ESCAPE OF AIR BETWEEN THE COIL AND THE OPPOSED WALLS. 